# Direct Time-of-Flight Measurement Accuracy Improvement With Perimeter-Gated SPADs

arXiv: https://arxiv.org/abs/2607.02546 · HTML: https://mlsanity.com/paper/2607.02546/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 1 of its 33 references that are in the map.
- First posted on arXiv 24 Jun 2026.

## Builds on (most cited first, 1 of 1)

- [A direct time-of-flight image sensor with in-pixel surface detection and dynamic vision](https://mlsanity.com/paper/2209.11772/) (2022)

## Abstract (arXiv)

Direct time of flight (dToF) measurements are susceptible to errors because of system-level and circuit-level timing jitters. In addition, device-level uncertainty stemming from the dark noise of single-photon avalanche diode (SPAD) contributes to the aggregated error. We demonstrate that perimeter gating can help reduce the device-level detection inaccuracy for SPAD devices by reducing the dark noise probability. Specifically, in this work, we developed a general framework to accurately estimate the dToF jitters stemming from different source levels and analyzed a counter-based time to digital converter (TDC) circuit that are commonly used in such systems. We have also measured dToFs using a perimeter-gated SPAD (pg-SPAD) detector fabricated in a 0.35 μm standard CMOS process. Experimental results show that pg-SPADs can improve measurement accuracy in both free-running and time-gated operations.